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ASU Scholarship Showcase


This growing collection, which contains many open access articles, consists of scholarly works authored by ASU community members. ASU-affiliated authors, who wish to deposit scholarly works, please use the Deposit form to describe your work.


Date Range
2006 2018


MALDI-TOF MS has been utilized as a reliable and rapid tool for microbial fingerprinting at the genus and species levels. Recently, there has been keen interest in using MALDI-TOF MS beyond the genus and species levels to rapidly identify antibiotic resistant strains of bacteria. The purpose of this study was to enhance strain level resolution for Campylobacter jejuni through the optimization of spectrum processing parameters using a series of designed experiments. A collection of 172 strains of C. jejuni were collected from Luxembourg, New Zealand, North America, and South Africa, consisting of four groups of antibiotic resistant isolates. The groups ...

Contributors
Penny, Christian, Grothendick, Beau, Zhang, Lin, et al.
Created Date
2016-05-31

Cyanovirin-N (CV-N) is an antiviral lectin with potent activity against enveloped viruses, including HIV. The mechanism of action involves high affinity binding to mannose-rich glycans that decorate the surface of enveloped viruses. In the case of HIV, antiviral activity of CV-N is postulated to require multivalent interactions with envelope protein gp120, achieved through a pseudo-repeat of sequence that adopts two near-identical glycan-binding sites, and possibly involves a 3D-domain-swapped dimeric form of CV-N. Here, we present a covalent dimer of CV-N that increases the number of active glycan-binding sites, and we characterize its ability to recognize four glycans in solution. A ...

Contributors
Woodrum, Brian, Maxwell, Jason, Allen, Denysia, et al.
Created Date
2016-06-06

A structurally and compositionally well-defined and spectrally tunable artificial light-harvesting system has been constructed in which multiple organic dyes attached to a three-arm-DNA nanostructure serve as an antenna conjugated to a photosynthetic reaction center isolated from Rhodobacter sphaeroides 2.4.1. The light energy absorbed by the dye molecules is transferred to the reaction center, where charge separation takes place. The average number of DNA three-arm junctions per reaction center was tuned from 0.75 to 2.35. This DNA-templated multichromophore system serves as a modular light-harvesting antenna that is capable of being optimized for its spectral properties, energy transfer efficiency, and photostability, allowing ...

Contributors
Dutta, Palash, Levenberg, Symon, Loskutov, Andrey, et al.
Created Date
2014-11-26

We propose a novel, efficient approach for obtaining high-quality experimental designs for event-related functional magnetic resonance imaging (ER-fMRI), a popular brain mapping technique. Our proposed approach combines a greedy hill-climbing algorithm and a cyclic permutation method. When searching for optimal ER-fMRI designs, the proposed approach focuses only on a promising restricted class of designs with equal frequency of occurrence across stimulus types. The computational time is significantly reduced. We demonstrate that our proposed approach is very efficient compared with a recently proposed genetic algorithm approach. We also apply our approach in obtaining designs that are robust against misspecification of error ...

Contributors
Kao, Ming-Hung, Mittelmann, Hans, College of Liberal Arts and Sciences, et al.
Created Date
2013-11-30

Transmission systems are under stress and need to be upgraded. Better utilization of the existing grid provides a fast and cheap alternative to building new transmission. One way to improve the utilization of the transmission network is power flow control via flexible AC transmission system (FACTS) devices. While FACTS devices are used today, the utilization of these devices is limited; traditional dispatch models (e.g., security con-strained economic dispatch) assume a fixed, static transmission grid even though it is rather flexible. The primary barrier is the complexity that is added to the power flow problem. The mathe-matical representation of the DC ...

Contributors
Sahraei-Ardakani, Mostafa, Hedman, Kory, Ira A. Fulton Schools of Engineering, et al.
Created Date
2015-07

Nonuniform Fourier data are routinely collected in applications such as magnetic resonance imaging, synthetic aperture radar, and synthetic imaging in radio astronomy. To acquire a fast reconstruction that does not require an online inverse process, the nonuniform fast Fourier transform (NFFT), also called convolutional gridding, is frequently employed. While various investigations have led to improvements in accuracy, efficiency, and robustness of the NFFT, not much attention has been paid to the fundamental analysis of the scheme, and in particular its convergence properties. This paper analyzes the convergence of the NFFT by casting it as a Fourier frame approximation. In so ...

Contributors
Gelb, Anne, Song, Guohui, College of Liberal Arts and Sciences, et al.
Created Date
2013-11-30

Decoding motor intent from recorded neural signals is essential for the development of effective neural-controlled prostheses. To facilitate the development of online decoding algorithms we have developed a software platform to simulate neural motor signals recorded with peripheral nerve electrodes, such as longitudinal intrafascicular electrodes (LIFEs). The simulator uses stored motor intent signals to drive a pool of simulated motoneurons with various spike shapes, recruitment characteristics, and firing frequencies. Each electrode records a weighted sum of a subset of simulated motoneuron activity patterns. As designed, the simulator facilitates development of a suite of test scenarios that would not be possible ...

Contributors
Abdelghani, Mohamed N., Abbas, James, Horch, Kenneth W., et al.
Created Date
2014-11-14

Laboratory investigations into the amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd), have accelerated recently, given the pathogen’s role in causing the global decline and extinction of amphibians. Studies in which host animals were exposed to Bd have largely assumed that lab-maintained pathogen cultures retained the infective and pathogenic properties of wild isolates. Attenuated pathogenicity is common in artificially maintained cultures of other pathogenic fungi, but to date, it is unknown whether, and to what degree, Bd might change in culture. We compared zoospore production over time in two samples of a single Bd isolate having different passage histories: one maintained in ...

Contributors
Langhammer, Penny, Lips, Karen R., Burrowes, Patricia A., et al.
Created Date
2013-10-10

Antigen-antibody complexes are central players in an effective immune response. However, finding those interactions relevant to a particular disease state can be arduous. Nonetheless many paths to discovery have been explored since deciphering these interactions can greatly facilitate the development of new diagnostics, therapeutics, and vaccines. In silico B cell epitope mapping approaches have been widely pursued, though success has not been consistent. Antibody mixtures in immune sera have been used as handles for biologically relevant antigens, but these and other experimental approaches have proven resource intensive and time consuming. In addition, these methods are often tailored to individual diseases ...

Contributors
Whittemore, Kurt, Johnston, Stephen, Sykes, Kathryn, et al.
Created Date
2016-06-14

Polymerases that synthesize artificial genetic polymers hold great promise for advancing future applications in synthetic biology. However, engineering natural polymerases to replicate unnatural genetic polymers is a challenging problem. Here we present droplet-based optical polymerase sorting (DrOPS) as a general strategy for expanding polymerase function that employs an optical sensor to monitor polymerase activity inside the microenvironment of a uniform synthetic compartment generated by microfluidics. We validated this approach by performing a complete cycle of encapsulation, sorting and recovery on a doped library and observed an enrichment of ∼1,200-fold for a model engineered polymerase. We then applied our method to ...

Contributors
Larsen, Andrew, Dunn, Matthew, Hatch, Andrew, et al.
Created Date
2016-04-05